The 1-byte write was silently clearing a byte on the stack.
If there was another function call with more arguments
in the same stack frame, no harm done.
Otherwise, if the variable at that location was already zero,
no harm done.
Otherwise, problems.
Fixes#8139.
LGTM=dsymonds
R=golang-codereviews, dsymonds
CC=golang-codereviews, iant, r
https://golang.org/cl/100940043
This is a workaround - the code should be better than this - but the
fix avoids generating large numbers of linehist entries for the wrapper
functions that enable interface conversions. There can be many of
them, they all happen at the end of compilation, and they can all
share a linehist entry.
Avoids bad n^2 behavior in liblink.
Test case in issue 8135 goes from 64 seconds to 2.5 seconds (still bad
but not intolerable).
Fixes#8135.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/104840043
If we see a typedef to an anonymous struct more than once,
presumably in two different Go files that import "C", use the
same Go type name.
Fixes#8133.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/102080043
Right now, any revision on the default branch after go1.3beta2 is
described by "go verson" as go1.3beta2 plus some revision.
That's OK for now, but once go1.3 is released, that will seem wrong.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/98650046
This program has barely been touched since it was first committed,
and in its current state it opens a code execution vector similar
to the one that was recently fixed in go.tools/playground/socket.
Rather than try to make it secure, remove it.
LGTM=minux, rsc
R=rsc, minux
CC=golang-codereviews
https://golang.org/cl/102030047
We were requiring that the defer stack and the panic stack
be completely processed, thinking that if any were left over
the stack scan and the defer stack/panic stack must be out
of sync. It turns out that the panic stack may well have
leftover entries in some situations, and that's okay.
Fixes#8132.
LGTM=minux, r
R=golang-codereviews, minux, r
CC=golang-codereviews, iant, khr
https://golang.org/cl/100900044
C globals are conservatively scanned. This helps
avoid false retention, especially for 32 bit.
LGTM=rsc
R=golang-codereviews, khr, rsc
CC=golang-codereviews
https://golang.org/cl/102040043
The 'continuation pc' is where the frame will continue
execution, if anywhere. For a frame that stopped execution
due to a CALL instruction, the continuation pc is immediately
after the CALL. But for a frame that stopped execution due to
a fault, the continuation pc is the pc after the most recent CALL
to deferproc in that frame, or else 0. That is where execution
will continue, if anywhere.
The liveness information is only recorded for CALL instructions.
This change makes sure that we never look for liveness information
except for CALL instructions.
Using a valid PC fixes crashes when a garbage collection or
stack copying tries to process a stack frame that has faulted.
Record continuation pc in heapdump (format change).
Fixes#8048.
LGTM=iant, khr
R=khr, iant, dvyukov
CC=golang-codereviews, r
https://golang.org/cl/100870044
Update #2675
The code here was using the error check for Linux/386,
not the one for FreeBSD/386. Most of the time it worked.
Thanks to Neel Natu (FreeBSD developer) for finding this.
The s/JCC/JAE/ a few lines later is a no-op but makes the
test match the rest of the file. Why we write JAE instead of JCC
I don't know, but the two are equivalent and the file might
as well be consistent.
LGTM=bradfitz, minux
R=golang-codereviews, bradfitz, minux
CC=golang-codereviews
https://golang.org/cl/99680044
This CL forces the optimizer to preserve some memory stores
that would be redundant except that a stack scan due to garbage
collection or stack copying might look at them during a function call.
As such, it forces additional memory writes and therefore slows
down the execution of some programs, especially garbage-heavy
programs that are already limited by memory bandwidth.
The slowdown can be as much as 7% for end-to-end benchmarks.
These numbers are from running go1.test -test.benchtime=5s three times,
taking the best (lowest) ns/op for each benchmark. I am excluding
benchmarks with time/op < 10us to focus on macro effects.
All benchmarks are on amd64.
Comparing tip (a27f34c771cb) against this CL on an Intel Core i5 MacBook Pro:
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 3876500413 3856337341 -0.52%
BenchmarkFannkuch11 2965104777 2991182127 +0.88%
BenchmarkGobDecode 8563026 8788340 +2.63%
BenchmarkGobEncode 5050608 5267394 +4.29%
BenchmarkGzip 431191816 434168065 +0.69%
BenchmarkGunzip 107873523 110563792 +2.49%
BenchmarkHTTPClientServer 85036 86131 +1.29%
BenchmarkJSONEncode 22143764 22501647 +1.62%
BenchmarkJSONDecode 79646916 85658808 +7.55%
BenchmarkMandelbrot200 4720421 4700108 -0.43%
BenchmarkGoParse 4651575 4712247 +1.30%
BenchmarkRegexpMatchMedium_1K 71986 73490 +2.09%
BenchmarkRegexpMatchHard_1K 111018 117495 +5.83%
BenchmarkRevcomp 648798723 659352759 +1.63%
BenchmarkTemplate 112673009 112819078 +0.13%
Comparing tip (a27f34c771cb) against this CL on an Intel Xeon E5520:
BenchmarkBinaryTree17 5461110720 5393104469 -1.25%
BenchmarkFannkuch11 4314677151 4327177615 +0.29%
BenchmarkGobDecode 11065853 11235272 +1.53%
BenchmarkGobEncode 6500065 6959837 +7.07%
BenchmarkGzip 647478596 671769097 +3.75%
BenchmarkGunzip 139348579 141096376 +1.25%
BenchmarkHTTPClientServer 69376 73610 +6.10%
BenchmarkJSONEncode 30172320 31796106 +5.38%
BenchmarkJSONDecode 113704905 114239137 +0.47%
BenchmarkMandelbrot200 6032730 6003077 -0.49%
BenchmarkGoParse 6775251 6405995 -5.45%
BenchmarkRegexpMatchMedium_1K 111832 113895 +1.84%
BenchmarkRegexpMatchHard_1K 161112 168420 +4.54%
BenchmarkRevcomp 876363406 892319935 +1.82%
BenchmarkTemplate 146273096 148998339 +1.86%
Just to get a sense of where we are compared to the previous release,
here are the same benchmarks comparing Go 1.2 to this CL.
Comparing Go 1.2 against this CL on an Intel Core i5 MacBook Pro:
BenchmarkBinaryTree17 4370077662 3856337341 -11.76%
BenchmarkFannkuch11 3347052657 2991182127 -10.63%
BenchmarkGobDecode 8791384 8788340 -0.03%
BenchmarkGobEncode 4968759 5267394 +6.01%
BenchmarkGzip 437815669 434168065 -0.83%
BenchmarkGunzip 94604099 110563792 +16.87%
BenchmarkHTTPClientServer 87798 86131 -1.90%
BenchmarkJSONEncode 22818243 22501647 -1.39%
BenchmarkJSONDecode 97182444 85658808 -11.86%
BenchmarkMandelbrot200 4733516 4700108 -0.71%
BenchmarkGoParse 5054384 4712247 -6.77%
BenchmarkRegexpMatchMedium_1K 67612 73490 +8.69%
BenchmarkRegexpMatchHard_1K 107321 117495 +9.48%
BenchmarkRevcomp 733270055 659352759 -10.08%
BenchmarkTemplate 109304977 112819078 +3.21%
Comparing Go 1.2 against this CL on an Intel Xeon E5520:
BenchmarkBinaryTree17 5986953594 5393104469 -9.92%
BenchmarkFannkuch11 4861139174 4327177615 -10.98%
BenchmarkGobDecode 11830997 11235272 -5.04%
BenchmarkGobEncode 6608722 6959837 +5.31%
BenchmarkGzip 661875826 671769097 +1.49%
BenchmarkGunzip 138630019 141096376 +1.78%
BenchmarkHTTPClientServer 71534 73610 +2.90%
BenchmarkJSONEncode 30393609 31796106 +4.61%
BenchmarkJSONDecode 139645860 114239137 -18.19%
BenchmarkMandelbrot200 5988660 6003077 +0.24%
BenchmarkGoParse 6974092 6405995 -8.15%
BenchmarkRegexpMatchMedium_1K 111331 113895 +2.30%
BenchmarkRegexpMatchHard_1K 165961 168420 +1.48%
BenchmarkRevcomp 995049292 892319935 -10.32%
BenchmarkTemplate 145623363 148998339 +2.32%
Fixes#8036.
LGTM=khr
R=golang-codereviews, josharian, khr
CC=golang-codereviews, iant, r
https://golang.org/cl/99660044
The rtype struct is meant to be a copy of reflect.rtype. The
zero field was added to reflect.rtype in 18495:6e50725ac753.
LGTM=rsc
R=khr, rsc
CC=golang-codereviews
https://golang.org/cl/93660045
[Same as CL 102820043 except applied changes to 6g/gsubr.c
also to 5g/gsubr.c and 8g/gsubr.c. The problem I had last night
trying to do that was that 8g's copy of nodarg has different
(but equivalent) control flow and I was pasting the new code
into the wrong place.]
Description from CL 102820043:
The 'nodarg' function is used to obtain a Node*
representing a function argument or result.
It returned a brand new Node*, but that violates
the guarantee in most places in the compiler that
two Node*s refer to the same variable if and only if
they are the same Node* pointer. Reestablish that
invariant by making nodarg return a preexisting
named variable if present.
Having fixed that, avoid any copy during x=x in
componentgen, because the VARDEF we emit
before the copy marks the lhs x as dead incorrectly.
The change in walk.c avoids modifying the result
of nodarg. This was the only place in the compiler
that did so.
Fixes#8097.
LGTM=khr
R=golang-codereviews, khr
CC=golang-codereviews, iant, khr, r
https://golang.org/cl/103750043
Breaks 386 and arm builds.
The obvious reason is that this CL only edited 6g/gsubr.c
and failed to edit 5g/gsubr.c and 8g/gsubr.c.
However, the obvious CL applying the same edit to those
files (CL 101900043) causes mysterious build failures
in various of the standard package tests, usually involving
reflect. Something deep and subtle is broken but only on
the 32-bit systems.
Undo this CL for now.
««« original CL description
cmd/gc: fix x=x crash
The 'nodarg' function is used to obtain a Node*
representing a function argument or result.
It returned a brand new Node*, but that violates
the guarantee in most places in the compiler that
two Node*s refer to the same variable if and only if
they are the same Node* pointer. Reestablish that
invariant by making nodarg return a preexisting
named variable if present.
Having fixed that, avoid any copy during x=x in
componentgen, because the VARDEF we emit
before the copy marks the lhs x as dead incorrectly.
The change in walk.c avoids modifying the result
of nodarg. This was the only place in the compiler
that did so.
Fixes#8097.
LGTM=r, khr
R=golang-codereviews, r, khr
CC=golang-codereviews, iant
https://golang.org/cl/102820043
»»»
TBR=r
CC=golang-codereviews, khr
https://golang.org/cl/95660043
The 'nodarg' function is used to obtain a Node*
representing a function argument or result.
It returned a brand new Node*, but that violates
the guarantee in most places in the compiler that
two Node*s refer to the same variable if and only if
they are the same Node* pointer. Reestablish that
invariant by making nodarg return a preexisting
named variable if present.
Having fixed that, avoid any copy during x=x in
componentgen, because the VARDEF we emit
before the copy marks the lhs x as dead incorrectly.
The change in walk.c avoids modifying the result
of nodarg. This was the only place in the compiler
that did so.
Fixes#8097.
LGTM=r, khr
R=golang-codereviews, r, khr
CC=golang-codereviews, iant
https://golang.org/cl/102820043
Update #8112
Hide one-pass regexp API.
This means moving the code from regexp/syntax to regexp,
but it avoids being locked into the specific API chosen for
the implementation.
It also removes a slice field from the syntax.Inst, which
should avoid bloating the memory footprint of a non-one-pass
regexp unnecessarily.
LGTM=r
R=golang-codereviews, r
CC=golang-codereviews, iant
https://golang.org/cl/98610046
For incomplete struct S, C.T and C.struct_S were interchangeable in Go 1.2
and earlier, because all incomplete types were interchangeable
(even C.struct_S1 and C.struct_S2).
CL 76450043, which fixed issue 7409, made different incomplete types
different from Go's point of view, so that they were no longer completely
interchangeable.
However, imprecision about C.T and C.struct_S - really the same
underlying C type - is the one behavior enabled by the bug that
is most likely to be depended on by existing cgo code.
Explicitly allow it, to keep that code working.
Fixes#7786.
LGTM=iant, r
R=golang-codereviews, iant, r
CC=golang-codereviews
https://golang.org/cl/98580046
Also made it extra clear for goto statements (even though label scopes
are already limited to the function defining a label).
Fixes#8040.
LGTM=r, rsc
R=r, rsc, iant, ken
CC=golang-codereviews
https://golang.org/cl/99550043
Map iteration order issue. Go 1.2 and earlier had stable results
for small maps.
Fixes#8115
LGTM=r, rsc
R=golang-codereviews, r
CC=dsymonds, golang-codereviews, iant, rsc
https://golang.org/cl/98580047
This matters for NaCl, which seems to swamp my 4-core MacBook Pro otherwise.
It's not a correctness problem, just a usability problem.
LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/98600046
CL 51010045 fixed the first one of these:
cmd/gc: return canonical Node* from temp
For historical reasons, temp was returning a copy
of the created Node*, not the original Node*.
This meant that if analysis recorded information in the
returned node (for example, n->addrtaken = 1), the
analysis would not show up on the original Node*, the
one kept in fn->dcl and consulted during liveness
bitmap creation.
Correct this, and watch for it when setting addrtaken.
Fixes#7083.
R=khr, dave, minux.ma
CC=golang-codereviews
https://golang.org/cl/51010045
CL 53200043 fixed the second:
cmd/gc: fix race build
Missed this case in CL 51010045.
TBR=khr
CC=golang-codereviews
https://golang.org/cl/53200043
This CL fixes the third. There are only three nod(OXXX, ...)
calls in sinit.c, so maybe we're done. Embarassing that it
took three CLs to find all three.
Fixes#8028.
LGTM=khr
R=golang-codereviews, khr
CC=golang-codereviews, iant
https://golang.org/cl/100800046
In the first very rough draft of the reordering code
that was introduced in the Go 1.3 cycle, the pre-allocated
temporary for a ... argument was held in n->right.
It moved to n->alloc but the code avoiding n->right
was left behind in order.c. In copy(x, <-c), the receive
is in n->right and must be processed. Delete the special
case code, removing the bug.
Fixes#8039.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/100820044
The code was assuming that pointer alignment is the
maximum alignment, but on NaCl uint64 alignment is
even more strict.
Brad checked in the test earlier today; this fixes the build.
Fixes#7863.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/98630046
The code cannot have worked before, because it was
trying to use the old value in a range check for the new
type, which might have a different representation
(hence the 'internal compiler error').
Fixes#8073.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/98630045
Common mistake (at least for me) because hg etc. require the prefix
while the go command forbids it.
Before:
% go get http://code.google.com/p/go.text/unicode/norm
package http:/code.google.com/p/go.text/unicode/norm: unrecognized import path "http:/code.google.com/p/go.text/unicode/norm"
After:
% go get http://code.google.com/p/go.text/unicode/norm
package http:/code.google.com/p/go.text/unicode/norm: "http://" not allowed in import path
LGTM=ruiu, rsc
R=rsc, ruiu
CC=golang-codereviews
https://golang.org/cl/97630046
